Hard and soft switching of PWM converters

[@KhunroongPHD]

This is gold mine of knowledge. Thanks Mr. Yaakov

[@sambenyaakov]

Thank you for comment.

[@srini1635]

You sir, are a legend for delivering such good educational content. 🙏 saved me hours of research.

[@sambenyaakov]

😊🙏

[@nikolaradakovic5050]

Prof. Yaakov, how can I thank you for this video. You have saved me countless nights of research

[@sambenyaakov]

Thanks for comment

[@nabilkerbila6467]

how can we calculate the phase shift between the control signals of the transistors to ensure the ZVS ?

[@sambenyaakov]

Best way by simulation.

[@nabilkerbila6467]

Thank you for your response, your video helps me a lot 👍

[@bala0486]

At 27:15, i can see a capacitor in series with inductor. But this capacitor was removed in further explanations. May i know the reason for the absence of this capacitor. Will this converter be still a resonant converter even in the absence of this series capacitor.?

[@sambenyaakov]

You have a keen eye. The capacitor is used to avoid average DC voltage on the transformer. If, however, one uses PCM control than the capcitor may not be needed.

[@avin6602]

Thanks! Is that snubber can be implemented in buck or fly-back as well?

[@sambenyaakov]

Yes

[@movax20h]

Super useful video. It looks I accidentally re-discovered the active phase shifted PWM when I was designing my inverter circuit. I knew it was probably extensively explored in literature, but I just was having fun playing with timings myself to improve the circuit. I think it is very elegant, and with DSP control it is also really easy to tweak. One can for example actively monitor voltages at the switching nodes, and figure out when is the right time to do transitions as quickly as possible.

[@sambenyaakov]

Good points. Thanks.

[@sudarshanpoudyal5089]

Does the same principle is applied to phase shift half bridge inverter....

[@sambenyaakov]

Yes

[@ezechatkiewicz]

Thank you Mr. Yaakov! This is explained so well! I can't thank you enough!

[@sambenyaakov]

😊Thanks

[@nduduzongcobo5941]

@@sambenyaakov Good explanation, it's like you teaching grade R ,which is what we need as students.People like you transfer knowledge from one generation to another.

[@ekus6196]

I would like to thank you for the excellent material presented in all your lectures . I am a little puzzled at 24.56 in this lecture . If I have followed your reasoning correctly , then I think that Vin > 1/2Vo should be Vin < 1/2Vo in order to reset the capacitor to at least Vin . Please correct me if I am wrong .

[@sambenyaakov]

Hi, Thank for comment and for finding the error. Yes, you are absolutely correct. A slip of the tongue.

[@stanislavsubrt886]

I dont know what to say except WOW. This is extremely high level educational content, exceptional explanation. Im watching your presentations instead of my favorite movies in the evening! Thank you!!!

[@sambenyaakov]

Thanks for e kind comment. I hope this does not mean that the videos put you to sleep😉

[@dallinlloyd7614]

You do an excellent job of explaining voltage snubbers in this video! I am trying to create a LT Spice model to simulate different snubber configurations and view the timing so I can gain more experience. One of the questions I now have is: How can I be sure I have selected an appropriate diode for the application? (short of building it in hardware and testing it for magic smoke)

[@sambenyaakov]

Recent SPICE and LTspice diodes are pretty specific diode functions.

[@mohamedbehery3433]

Thank you sir, I believe this is one of the best youtube channels featuring graduate level topics on power electronics.

[@sambenyaakov]

Thanks

[@ericpersson8753]

Sam - on the very first slide, you show two different hand-drawn graphs both labeled "ID". One appears to be the switch drain current, the other appears to be diode current including reverse recovery (also drawn below the schematic with an inductor labeled Ls instead of Lm like in the schematic). They are completely different. The schematic does not have any label defining what is ID? This is confusing to a student trying to learn this for the first time. Please make sure that variables are uniquely identified, and properly labeled in the schematic.

[@sambenyaakov]

Noted

[@alexnoggle1874]

Great presentation, learned a ton!

[@sambenyaakov]

Thanks

[@bekanadiradze9668]

Nice explanation. Horrible drawings.

[@sambenyaakov]

Would you rather have nice drawings and terrible explanation?🙃

[@bekanadiradze9668]

@@sambenyaakov I'd like them both to be nice :)

[@sambenyaakov]

@@bekanadiradze9668 👍

[@johnaweiss]

Who is the teacher that would prepare me to understand Sam Ben-Yaakov?

[@sambenyaakov]

🤔

[@johnaweiss]

@@sambenyaakov I love your lessons, the problem is me. I lack certain requisite understanding.

[@sambenyaakov]

@@johnaweiss Keep watching and look for my earlier videos which cover the basics

[@esijal]

Great explanations, best wishes for you.

[@sambenyaakov]

Thanks

[@romma11]

should it be refereed as ZCS as opposed to 'ZVS at turnoff'

[@sambenyaakov]

To which minute in video are you referring to?

[@romma11]

Hi, at 16:50. Probably just words game, but closed fet already has 0v, so any openings of fet you want to happen at zero current, and closing at zero v. Thanks for sharing your lectures!

[@sambenyaakov]

@@romma11 In this case, the FET is conducting so there is a current passing through it. Tp achive ZCS you need an auxiliary switch that will force the current to zero (by re-routing it) at this part I am considering passive solutions.

[@RicardoPenders]

I've built a ZVS driver using the third option the passive lossless snubber because I need the capacitor to dump all its energy at once in the primary coil of my flyback, the flyback produces about 150KV, I can pull 15cm very hot plasma arcs with it... You're absolutely right about the safety, it's very very dangerous indeed. But a lot of fun to play with.

[@sambenyaakov]

👍

[@martinmotal.581]

you are really a Proffesor,good and clear explaning. Thanks and I apologizze for my ugly english. Para Sam Hijo de Jacobo Shalom.

[@sambenyaakov]

Hi Martin, Thanks. Perdón por el mal español

[@quanquanlive]

Thanks professor. This is very very helpful for understanding soft switching.

[@sshanto17]

Thank you Professor Ben-Yaakov. I hold a respect for you and your content. The level of details captured in your video series are very useful in understanding real world circuits

[@sambenyaakov]

Thanks

[@habtamusium8646]

many thanks! Prof. SBY , i am getting energy through your lectures ! may God return to the best one of your prayers !

[@sambenyaakov]

Thanks.

[@thejunouyang]

Thank you for the very detailed information. Could you explain what is the topology of the last converter? It look different than a boost and the transformer doesn't allow DC to pass through.

[@sambenyaakov]

Please indicate the minute of video you are referring to.

[@thejunouyang]

28:00 Thank you.

[@georgematthew1]

Thanks!

[@sambenyaakov]

😊🙏

[@quyenangcao5744]

the video is great. I hope you will put it in a list so we can watch in order instead of one by one.

[@sambenyaakov]

You can use www.advicepoweracademy.com/video-tutorials for older videos

[@hilalsankari149]

very clear and useful, thank you dear professor.

[@sambenyaakov]

Thanks for kind note.

[@EhsanHabib]

Thank You Sir for Time and Knowledge

[@sambenyaakov]

Thanks for comment.

[@ingDemurtas]

such a clever way of reducing losses. Thanks for the lesson

[@sambenyaakov]

😊

[@anshaggarwal2060]

Hallo Prof. Ben-Yaakov, I have been using your videos to understand these important concepts. Could you please share the books (papers) you referred to for making this video?

[@sambenyaakov]

Thanks for comments. I am not aware of Books that present the subjects as I do.

[@Rev22-21]

Now i know I am glad I watched this.

[@sambenyaakov]

Thanks

[@elye3701]

I sometimes find it confusing trying to follow your thoughts because I don't have a clue where your pen is pointing to. That said, it was very enlightening to know warts and all about the reality of circuits and their components. Have you given any thought about the same topic but done with vacuum tubes instead? Would they perform better or worse? Could you do a video on the Ćuk converter? Other video suggestion would be protection at the input and at the output when power is lost or load is disconnected or developes a short. Thanks.

[@sambenyaakov]

I am sorry, some of the older videos did not record the pen movement. Too late to correct.

[@sravanthik2402]

Respected professor I am in confusion to select which type of converter. Isolated or no isolated or soft switching techniques for 1mw pv system. Can you help me where can I get all the information regarding DC DC converter.

[@sambenyaakov]

Hi, This is a too general question. You have to specify required output voltage. There might also be a problem of a start up.

[@terziwh]

Thanks professor, I was just wondering that in the first example you are using snubber in parallel to diode, doesn't this provide a path for current to flow in the reverse direction when the diode is in blocking mode?

[@sambenyaakov]

Only after reverse conduction of diode is completed. Before that the voltage of diode is still low.

[@ruixiong5237]

Great video. It really helps a lot.

[@sambenyaakov]

Thanks

[@muhammadnomanakbar5356]

Very helpful. Thanks

[@sambenyaakov]

Thanks

[@leozendo3500]

Wow I'm watching this for making an silent and efficient flyback transformer driver for fun.

[@sambenyaakov]

Thanks

[@n6mz]

Excellent, thank you. I wish I could have been one of your students.

[@sambenyaakov]

😊I guess it is impossible as yet to go forward to the past.

[@ANoNIMkillir]

Thanks for the video. I got question about turn-off losses of PSFB converter, since with the ZVS we get rid off only turn on losses. What part of losses is turn-of losses? Thanks!

[@sambenyaakov]

Overlap between dt/dt and di/dt

[@ANoNIMkillir]

@@sambenyaakov Sorry, I asked question wrong. I had in mind the following: what part of the loss falls on turning-on and which on turning-off of the the transistor. What is more significant loss on turning-on or loss on turning-off or they equal? In datasheet of the transistor there is Eon and Eoff - parameters, where Eoff>Eon. Does this mean turn-off losses more than turn-on losses?

[@zz9758]

thank you ! professor! As i know from your lecture , the circuit from M.domb,R,Redl and N.sokal just reduced VDS slope when FET turn off . it will not help to turn on .Am i correct?

[@sambenyaakov]

correrct

[@DOODI7100]

First thank u Sam, but why it will not help to turn on? I see it help in both switching sides (ON and OFF) by reduces Vds slope.

[@ekus6196]

@@DOODI7100 This circuit gives no advantage at switch-on . In fact, there is a slight disadvantage at switch-on because the voltage on the lossless capacitor must be reversed via the resonant circuit which results in a half sinusoidal current peak .

[@alocin110]

Thank you Prof. Ben-Yaakov, this is definitely one of the best elaborated video on the subject. I really helped me a lot understanding the techniques you presented and explained. I do have simulator software and your lecture saved me hours of work. Thank you so much for enlightening the knowledge by sharing your knowledge. I subscribed to your channel and also liked your videos. Thank you so much.

[@sambenyaakov]

Thank you. Comments like yours keep me going.

[@5430mr]

I really appreciate your simplified way of transferring data. Thanks a lot

[@sambenyaakov]

😊

[@darkcircles3]

Most grateful for your teachings. Thank you Prof. Ben-Yaakov.

[@sambenyaakov]

Thanks for comment.

[@babylonfive]

Thanks very much.

[@thanadthasainak8547]

Thank you.

[@tranxuandinh7152]

Thank you very much!

[@mhtavallaei2175]

Thank you prof.Yaakov Very useful video

[@sambenyaakov]

😊

[@chen9333]

Thank you ,by this video it's really easy to understand

[@sambenyaakov]

Thanks for comment.

[@cosmoalien12345]

Great

[@Azagro]

Very indepth information. Keep it up!

[@sambenyaakov]

Thanks for comment.

[@wariskn7096]

Please draw more clearly ..it's too clumsy..

[@sambenyaakov]

HI waris kn, let's make a deal, next videos I will send you my clumsy drawings, you will redraw them nicely and I will record the videos. OK?

[@wariskn7096]

@@sambenyaakov that's a great idea.....you are a genius!!!!!

[@mdasikkhan1610]

@@sambenyaakov LOL

[@FaraedoonWaly]

Thank you dear professor sam you are really a graet academic person in terms of knowledge and explain with aging experiences and sharing all in simple way.

[@sambenyaakov]

😊Thanks

[@nikolade112]

Thank you Professor. Thanks a lot !

[@sambenyaakov]

Thanks for comment

[@seshansesha7645]

Nice and simple..thanks

[@sambenyaakov]

Thank you.